<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"> 
<title>css3基础</title> 
<style> 
.button {
    background-color: white;
    border: 2px solid #4CAF50;
    color: black; 
    padding: 16px 32px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
    margin: 4px 2px;
    -webkit-transition-duration: 0.4s; /* Safari */
    transition-duration: 0.5s;
    cursor: pointer;
}
.button:hover {
    background-color: #4CAF50;
    color: white;
}
</style>
</head>
<body>

<buttom class="button button1">2px</buttom>

</body>
</html>